Actually, the belt-fed in the picture is Len Savage's semiautomatic belt-fed Bren gun - maybe his prototype that I think he was showing off a few years ago.
If you look closely you can see the Bren elements in the barrel, gas block, carrying handle, bipod, buttstock, etc...
Now then, that said are high capacity semiautos with pistol grips legal in Illinois?
Frank Exchange of Views